This invention relates to improvements in manhole frames (or barrels) and covers.
Manholes which are used in roadways, sidewalks and the like traditionally are provided with heavy cast iron or like lift-off covers which fit on a barrel-like metal frame at the top of the manhole just below the road or sidewalk surface. Manhole structures provide access to underground sewer, storm, telephone, electric and other utilities. Commonly such frames have an outwardly extending peripheral flange at the bottom which rests on top of a concrete or other manhole cone. During construction of a roadway or sidewalk, difficulties may be encountered in ensuring that the top of the manhole frame is suitably flush and level with the roadway or sidewalk surface insofar as adjustments in the height and/or tilt of the manhole frame involve manipulation in situ of a relatively heavy cast iron or like barrel. In order to provide height adjustments therefore, use is often made of ring-like metal risers placed on the manhole frame. The risers add to the expense of a manhole structure and may tend to buckle with extended usage.